Last week Yahoo officially confirmed about major data breach – more than 500 million accounts were leaked in 2014. This incident raised many questions. How is it possible that Yahoo hasn’t noticed the attack earlier? Why did they take so long? Why don’t we have detailed explanations yet? The first rumours about Yahoo hack started in the middle of summer. The company claimed that 280 million accounts information might have been hacked. Then, Yahoo launched an investigation and disappeared. Last week they finally published a press release. Surprisingly after the investigation the size of hacked accounts doubled. In the official statement, the company spread concern and mostly talked how users should secure their accounts. The announcement initiated many discussions and negatively affected Yahoo image. According to Financial Times, on Monday Yahoo stock value decreased by 3.75% since the announcement day, 22nd of September.

Nowadays data breach is a growing cyber security problem. This year we have already heard about several attacks on popular social networks Tumblr, LinkedIn, and MySpace. Hackers stole more than 65 million Tumblr, 164 million LinkedIn and 360 million MySpace accounts. The amount of hacked data is enormous, but it still cannot be compared with a massive Yahoo leak. However, the investigations of these attacks have one thing in common. The social networks were hacked in 2012 and 2013, but information about it shown up only this year. Indeed, it’s hard to understand how these attacks were unnoticed. A few days ago USA Senators asked for more details on Yahoo data breach and asked Securities and Exchange Commission to open an investigation on this issue. Hopefully, soon we will get explanation about the biggest data breach in the history.

Yahoo hasn’t delivered clear explanation why the attack occurred or why they took so long to notice it. The company only briefly mentions that state might be responsible for the attack because of political reasons. This assumption might be correct, but it doesn’t explain attempts to sell this data on the dark web. Indeed, for almost two years millions of users’ names, surnames, birthdays, telephone numbers, security questions and answers have been known on the dark web. Luckily, bank account information hasn’t been leaked, and users don’t need to worry about money loss. However, there are many other things to worry about.

Massive data breach created serious concerns about cyber security and credibility of the Yahoo. Web giants always claim that users’ safety is a top priority. Unfortunately, this incident made many people doubt it. Last week Marissa Mayer, CEO of Yahoo, revealed that she knew about the data breach announced in July. Since then Yahoo received many questions and accusations of delaying data breach revelation. After the attack, all computer users are encouraged to strengthen their online security. Make sure you are using strong and different passwords to access various online services.